I might recommend taking highway 40 east out of Steamboat Springs over Rabitt Ears Pass. Stay on it until you're just outside of Granby. Then, take highway 125 north. (It only goes one direction at the intersetion- don't go south, you'll be in Granby resevoir
This is a really scenic, leisurely drive over willow creek pass.
In about 45 miles you will be in the town of Walden. Walden is a ranching community and is what the REAL Colorado is like. (Walden is in Jackson county, and there isn't a stop light in the entire county)
There is a great cafe on main street called The Coffee Pot. You can't miss it, Main Street is about three blocks long.
Food there is really good, not great, but down home comfort food. Salad bar with a potato salad the cook won an award for. And it is good.
Walden also has an incredible Frontier Museum that is amazing for a town of its size (500), and its free. Just ask someone where to find it, its one block off of main street.
After your visit, hop back on 125 north and it takes you to Laramie, about 40 miles. From there I believe you can get on the interstate to Cheyenne.
I live in Colorado, and this is the route I would sure take.
Hope this helps!